How to cite: Berninger, Benedikt. “Causality and the Brain.” In: “Environment, Culture, and the

Brain: New Explorations in Neurohistory,” edited by Edmund Russell, RCC Perspectives 2012, no. 6, 23–25.

All issues of RCC Perspectives are available online. To view past issues, and to learn more about the

Rachel Carson Center for Environment and Society, please visit www.rachelcarsoncenter.de.

Rachel Carson Center for Environment and Society

Leopoldstrasse 11a, 80802 Munich, GERMANY

ISSN 2190-8087

© Copyright is held by the contributing authors.

How to cite: Berninger, Benedikt. “Causality and the Brain,” In: “Environment, Culture, and the

Brain: New Explorations in Neurohistory,” edited by Edmund Russell, RCC Perspectives 2012, no. 6, 23–25.

All issues of RCC Perspectives are available online. To view past issues, and to learn more about the

Rachel Carson Center for Environment and Society, please visit www.rachelcarsoncenter.de.

Rachel Carson Center for Environment and Society

Leopoldstrasse 11a, 80802 Munich, GERMANY

ISSN 2190-8087

© Copyright is held by the contributing authors.

23Environment, Culture, and the Brain

Benedikt Berninger

Causality and the Brain

History, while shaped by a variety of non-human factors, is ultimately made by hu-

mans, whose actions, in terms of motivations and their capability of understanding

different situations, are intricably bound to the design (through biological evolution) of

their brains. Since antiquity, historians have faced the problem of explaining historic

events, such as the Peloponnesian War or the Second World War, by identifying the

causes that have led to them. Just as in the natural sciences, the concept of causality

is of fundamental importance to the science of history.

Yet it may be argued that the very concept of causality, rather than being a brain-

independent reality, may itself derive from the way the human brain encodes and

structures experience, that is, by changing the strength of the functional connectivity

between neurons according to inbuilt algorithms that themselves depend on the pre-

cise temporal order of neural activity (Berninger and Bi 2002). Immanuel Kant ([1765]

1965), in an attempt to solve a problem originally formulated most articulately by

David Hume ([1739] 1888), concluded that the notion of causality, rather than being

derived from experience, is an a priori condition of experience. He agrees with Hume

that the idea that a certain cause is followed by a certain effect with necessity cannot

be derived from experience: repeating the same experiment a hundred times does not

prove that the next time the result would be the same; rather, the notion of necessity

is a categorical condition for the notion of causality.

Needless to say, scientists are a long way from having a neurobiological explanation of

how our brain “computes” a kind of more categorical causality. We have proposed that,

at an elementary level, it may be related to the phenomenon of spike timing dependent

plasticity (STDP) of synapses (Berninger and Bi 2002). STDP is a phenomenon occur-

ring at many central synapses, for instance the so-called Schaffer collaterals in the hip-

pocampus, which play a crucial role in the formation of episodic memories (Bi and Poo

2001). A synapse between a neuron A and a neuron B becomes strengthened when the

firing of A precedes the firing of B within a narrow time window of few milliseconds. If

the temporal order is reversed, i.e., neuron B fires before it receives input from neuron

A, then the synapse becomes weakened. Anthropomorphically expressed, the synapse

24 RCC Perspectives

A to B becomes strengthened when it contributed to the firing of B and weakened when

it did not contribute. Thus, the synaptic modification rule appears to serve on a very

elementary level as a causation detection mechanism.

Why would considering the neurobiological basis of the cognitive category of causality

be relevant to the idea of neurohistory? Despite the fact that it obviously arose in adap-

tation to a real world, we cannot assume that a biologically implemented mechanism is

limitlessly applicable to all phenomena. In fact, there are examples of situations where an

appropriate description of the phenomena contradicts our commonsense understanding

of causality. The unpredictability of the exact moment of decay for a single radioactive

atom may be taken as an example par excellence of the failure of a strict causality in which

every subsequent moment is entirely determined by the previous one. Likewise, our mind

struggles with the view of physicists like Prigogone in the field of nonintegrable dynam-

ical systems who suggests: “Insofar as we are unable, not only in practice, but as a matter

of principle, to describe the system by a trajectory, and are forced to use a distribution

function corresponding to a finite (even arbitrarily small) region, we can only predict the

statistical fate of the system” (quoted in Balescu 2007, 27).

One might ask whether such reasoning can also be applied to the science of historical

processes: to consider historical processes as transitions between attractor states, see-

mingly stable, but constantly destabilized by mutually interacting and interdependent

factors. In a similar analogy, historical processes may be compared to the transition

between brain states: they are stable within short temporal windows, but are neces-

sarily transient and eventually result in persistent (but not necessarily permanent)

modifications of the circuitry, thereby modifying the attractor landscape itself, some-

times irreversibly. If, then, we consider history to share certain structural features with

nonintegrable dynamical systems, thus allowing the possibility for the emergence of

complex or chaotic behaviors, it would strongly suggest that we attribute an erroneous

degree of predictability to history when we try to isolate individual causal relationships

between single historical momenta of political and ideological nature.

These considerations serve to illustrate that our thinking is often restricted by common-

sense understanding, which is itself, not unsurprisingly, the result of the faculties and

limitations created by the design of our brain. One important task of neurohistory may

be to incorporate an awareness of these faculties and limitations into the way we think

about humankind and history.

25Environment, Culture, and the Brain

References

Balescu, Radu. 2007. “Ilya Prigogine: His Life, His Work.” In Special Volume in Memory of Ilya

Prigogine, edited by Stuart A. Rice, 1–82. Advances in Chemical Physics, vol. 135. Hoboken,

NJ: John Wiley and Sons.

Berninger, Benedikt, and Guo-Quiang Bi. 2002. “Synaptic Modification in Neural Circuits: A

Timely Action.” Bioessays 24 (3): 212–22.

Bi, Guo-Quiang, and Mu-Ming Poo. 2001. “Synaptic Modification by Correlated Activity: Hebb’s

Postulate Revisited.” Annual Review of Neuroscience 24: 139–66.

Hume, David. (1739) 1960. A Treatise of Human Nature. Edited by L. A. Selby-Bigge. Oxford:

Claredon Press.

Kant, Immanuel. (1765) 1965. Critique of Pure Reason. Translated by Norman Kemp Smith. New

York: St. Martin’s Press.

Prigogine, Ilya. 1997. The End of Certainty. New York: The Free Press. Originally published in

French as Le fin des certitudes.